In general, the invention relates to vehicle navigation. More specifically, the invention relates to a method of locating a given destination and in particular, to provide maneuver instructions to the destination while providing warning signs that a pending maneuver is approaching.
Current navigation systems require the user to input a starting point and a destination. Based on these two points, the navigation software accesses an existing map database, attempts to calculate the best route and provide detailed maneuvering instructions such as which street to turn onto and which direction to turn.
At times, the driver may miss the turn either because it is not known that the vehicle is approaching the street, or perhaps the street is not marked well with signs. It would be desirable to provide the driver with as much navigation information as possible, yet keep the transmitted information at a minimum to avoid burdening the navigation system with too much information. A method for determining concise information to be transmitted to the vehicle would then be desirable.
Thus, there is a significant need for a method for improving vehicle navigation so that providing vehicle navigation instructions may be more easily realized.
One aspect of the invention provides a method for providing vehicle navigation instructions. This method may include receiving a destination at a map database, and receiving a vehicle""s location. Next, this method may include calculating the distance between the vehicle location and the destination and calculating the distance between the destination and candidate maneuver alert road segments. Furthermore, this method may include determining the vehicle""s distance from the destination and planned direction of travel toward the destination. Additionally, a proximity region surrounding the destination may be determined within which to search the map database for road segments. If at least one road segment exists inside the proximity region and intersects the vehicle""s planned path of travel between the vehicle""s current location and the destination, a maneuver alert road segment closest to the destination may be determined. If at least one maneuver alert road segment is found, maneuver instructions from the maneuver alert road segment may be provided.
Another aspect of the invention provides a method for expanding the proximity region outward from the destination to provide a greater area within which to search the at least one database if at least one road segment is not found within the proximity region.
Another aspect of this invention provides a system for providing vehicle navigation instructions. This system includes means for means for searching an at least one database, for receiving a destination at a map database, and for receiving a vehicle""s current location. The system may also include means for calculating a distance between the vehicle location and the destination and for calculating a distance between the destination and candidate maneuver alert road segments. This system also includes means for determining a proximity region and whether at least one maneuver alert road segment exists within the proximity region. Furthermore, this system provides means for providing maneuver instructions from the closest maneuver alert road segment to the destination.
Another embodiment of this invention provides a system with means for expanding the proximity region if at least one maneuver alert road segment is not found within the proximity region.
A further aspect of this invention provides a computer usable medium for providing vehicle navigation instructions. This computer usable medium includes computer readable code to search a map database, to calculate required distances, to determine proximity areas and to determine whether at least one maneuver alert road segment exists within the proximity area. Another aspect of this computer usable medium provides computer readable code to expand the proximity area if at least one maneuver alert road segment is not found within the proximity area.
The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiment, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.